A fire caused about $30,000 in damage to a barn near Waltham Sunday night.

Mower County Sheriff Terese Amazi said Hayfield and Brownsdale firefighters responded to the barn fire at the 32100 area of Highway 56 in Waltham. Firefighters found the property owner had already cut power to the single story barn and the family had removed all livestock from the building.

Firefighters believe heat lamps set up for three calves in the corner of the barn caused the fire, according to Amazi. A section of the barn’s west side was destroyed, while a larger section of the east side sustained damage, Amazi said. None of the livestock appear to have died.